package io.github.bw.scorpio.common.reflect;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

public class PackageUtil {

  private PackageUtil() {
  }

  /**
   * 获取某包下（包括该包的所有子包）所有类
   *
   * @param packageName 包名
   * @return 类的完整名称
   */
  public static List<String> getClassName(String packageName) {
    return getClassName(packageName, true);
  }

  /**
   * 获取某包下所有类
   *
   * @param packageName  包名
   * @param childPackage 是否遍历子包
   * @return 类的完整名称
   */
  public static List<String> getClassName(String packageName, boolean childPackage) {
    return getClassName(packageName, Thread.currentThread().getContextClassLoader(), childPackage);
  }

  /**
   * 获取某包下所有类
   *
   * @param packageName  包名
   * @param childPackage 是否遍历子包
   * @return 类的完整名称
   */
  public static List<String> getClassName(String path, String packageName, ClassLoader classLoader,
      boolean childPackage) throws MalformedURLException {
    List<String> fileNames = null;
    String packagePath = packageName.replace(".", "/");
    URL url = new URL("file:" + path + "!" + packagePath);

    String type = url.getProtocol();
    if (type.equals("file")) {
      fileNames = getClassNameByFile(url.getPath(), null, childPackage);
      List<String> jarsNames = getClassNameByJars(((URLClassLoader) classLoader).getURLs(), packagePath, childPackage);
      fileNames.addAll(jarsNames);
    } else if (type.equals("jar")) {
      fileNames = getClassNameByJar(url.getPath(), childPackage);
    }
    return fileNames;
  }

  /**
   * 获取某包下所有类
   *
   * @param packageName  包名
   * @param childPackage 是否遍历子包
   * @return 类的完整名称
   */
  public static List<String> getClassName(String packageName, ClassLoader classLoader, boolean childPackage) {
    List<String> fileNames = null;
    String packagePath = packageName.replace(".", "/");
    URL url = classLoader.getResource(packagePath);
    if (url != null) {
      String type = url.getProtocol();
      if (type.equals("file")) {
        fileNames = getClassNameByFile(url.getPath(), null, childPackage);
        List<String> jarsNames = getClassNameByJars(((URLClassLoader) classLoader).getURLs(), packagePath,
            childPackage);
        fileNames.addAll(jarsNames);
      } else if (type.equals("jar")) {
        fileNames = getClassNameByJar(url.getPath(), childPackage);
      }
    } else {
      fileNames = getClassNameByJars(((URLClassLoader) classLoader).getURLs(), packagePath, childPackage);
    }
    return fileNames;
  }

  /**
   * 从项目文件获取某包下所有类
   *
   * @param filePath     文件路径
   * @param className    类名集合
   * @param childPackage 是否遍历子包
   * @return 类的完整名称
   */
  private static List<String> getClassNameByFile(String filePath, List<String> className, boolean childPackage) {
    List<String> myClassName = new ArrayList<>();
    File file = new File(filePath);
    File[] childFiles = file.listFiles();
    if (childFiles != null) {
      for (File childFile : childFiles) {
        if (childFile.isDirectory()) {
          if (childPackage) {
            myClassName.addAll(getClassNameByFile(childFile.getPath(), myClassName, childPackage));
          }
        } else {
          String childFilePath = childFile.getPath();
          if (childFilePath.endsWith(".class")) {
            if (childFilePath.contains("test-classes")) {
              continue;
            }
            if (childFilePath.contains("/")) {
              childFilePath = childFilePath.substring(childFilePath.indexOf("/classes") + 9,
                  childFilePath.lastIndexOf("."));
              childFilePath = childFilePath.replace("/", ".");
            } else {
              childFilePath = childFilePath.substring(childFilePath.indexOf("\\classes") + 9,
                  childFilePath.lastIndexOf("."));
              childFilePath = childFilePath.replace("\\", ".");
            }
            myClassName.add(childFilePath);
          }
        }
      }
    }

    return myClassName;
  }

  /**
   * 从jar获取某包下所有类
   *
   * @param jarPath      jar文件路径
   * @param childPackage 是否遍历子包
   * @return 类的完整名称
   */
  private static List<String> getClassNameByJar(String jarPath, boolean childPackage) {
    List<String> myClassName = new ArrayList<>();
    String[] jarInfo = jarPath.split("!");
    String jarFilePath = jarInfo[0].substring(jarInfo[0].indexOf("/"));
    String packagePath = jarInfo[1].substring(1);
    try (JarFile jarFile = new JarFile(jarFilePath)) {
      Enumeration<JarEntry> entryEnumeration = jarFile.entries();
      while (entryEnumeration.hasMoreElements()) {
        JarEntry jarEntry = entryEnumeration.nextElement();
        String entryName = jarEntry.getName();
        if (entryName.endsWith(".class")) {
          if (childPackage) {
            if (entryName.startsWith(packagePath)) {
              entryName = entryName.replace("/", ".").substring(0, entryName.lastIndexOf("."));
              myClassName.add(entryName);
            }
          } else {
            int index = entryName.lastIndexOf("/");
            String myPackagePath;
            if (index != -1) {
              myPackagePath = entryName.substring(0, index);
            } else {
              myPackagePath = entryName;
            }
            if (myPackagePath.equals(packagePath)) {
              entryName = entryName.replace("/", ".").substring(0, entryName.lastIndexOf("."));
              myClassName.add(entryName);
            }
          }
        }
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
    return myClassName;
  }

  /**
   * 从所有jar中搜索该包，并获取该包下所有类
   *
   * @param urls         URL集合
   * @param packagePath  包路径
   * @param childPackage 是否遍历子包
   * @return 类的完整名称
   */
  private static List<String> getClassNameByJars(URL[] urls, String packagePath, boolean childPackage) {
    List<String> myClassName = new ArrayList<>();
    if (urls != null) {
      for (URL url : urls) {
        String urlPath = url.getPath();
        // 不必搜索classes文件夹
        if (urlPath.endsWith("classes/")) {
          continue;
        }
        String jarPath = urlPath + "!/" + packagePath;
        myClassName.addAll(getClassNameByJar(jarPath, childPackage));
      }
    }
    return myClassName;
  }

}
